Mirror bandwidth and user redirection

From: Matt Domsch <Matt_Domsch dell com>

To: fedora-infrastructure-list redhat com

Subject: Mirror bandwidth and user redirection

Date: Mon, 30 Jun 2008 00:06:26 -0500

Tonight I deployed a slight update to MirrorManager that I'd been
wanting to do for a while. The basic selection algorithm for choosing
the order in which to return mirrors to clients remains the same:
prefer same netblocks, internet2 in same country if on internet2, same
country, same continent, then global, in that order. However, until
now, faster mirrors (those with larger bandwidths) were returned with
equal probability as slower mirrors. This means not enough traffic
was being sent to our gigabit-connected mirrors, and too much traffic
was being sent to our slower mirrors.
Each mirror's bandwidth value is now used as a weight. Mirrors with
larger bandwidth will have a a higher probability of being returned
earlier in the mirrorlist selection. Slower mirrors can still be
returned as the first mirrorlist selection because this is based on
probabilities, but should not be overwhelmed anymore.
For countries with fewer mirrors, such as India, where there's some
relatively fast mirrors, and several relatively slower mirrors, this
should mean that users will more often get directed to the faster
mirrors.
Thanks,
Matt
Fedora Mirror Wrangler
--
Matt Domsch
Linux Technology Strategist, Dell Office of the CTO
linux.dell.com & www.dell.com/linux